Telephone system



July 24, 1928.

H. C. CAVERLY TELEPHONE SYSTEM July 24, 1928.

1,678,103 H. c. cAvERLY TELEPHONE SYSTEM Filed oct. 4. 1927 4 sheets-sheet 2 @Wa/w Ana/MY.

,July 24, 192s.A

H. C. CAVERLY TELEPHONE SYSTEM Filed Oct. 4, 1927 Arm/Mfr July 24, 1928.

H. C. CAVERLY TELEPHONE SYSTEM Filed Oct. 4. 1927 4 Sheets-Sheet Afro/Mfr d Patented July 24,1928.`

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nanna" o.. onvirnny, or neste organen-NEW JERSEY; Assenoit ro BELL TLnriroNn tnisonaronrns, 'Inconronnmnn or New Yoan,k N. Y., A coPoit'rIn `or NEW YORK;

TELEPHONE fsYsTEM.

Thislinvcmtionv` relates to telephone exchange systems `and has tor its obJect the provision ofimproved means for automat-v elephone designations. l from one otlice to another, particularly Where an intermediate' or@ a tandem oiiice is em-l ically transmitting ployed whereby the establishment of such connections is simplilied andrfrendered less `subject to error. y y

, there a telephone connection has beenextcndedtrom a machine switching oillceto ka .manual oiiice through a 'tandem oiiice in theA past, it has been customary to transmit the` complete telephone designation toy the tandem ottice, Where the tandem operator selects an outgoing trunk and passes the called line number to` the distant oiiice,-orwhcre a tandem sender records the designation,

f employs the otlice code to select a trunk, andy retransmits the called line number to the rj distant otlce.

ln accordance with the present invent-ion, f

only the otlice code is transmitted to the tarif dem oiiice and the extension of 'the inter otlicc trunk to the distant oilice causes the transmission of the line number to such distant otlice. This obviates the necessity of repeating` the called line number either orally or mechanically and therefore lessensthe o chance of error due to' such repetition.

The invention finds one speciicembodiment in a system in `which the telephone designations are transmitted by4 means of a call announcer mechanism' located at an auto- ;:x matic oi'hce to a tandem operator and subsequently to a4 distantoperator. A series of counting; relays associate the call announcer mechanismivith the registers of the'sender y to cause the transmission, certain oi the seriesv beineemployed for the announcement of the oflice code and re-used tosubsequently announce the called line number.

, This specic embodiment isl illustrated in the accompanying drawings in Which Fig.

i5 l shon's a calling subscriberfs line in amechanical oilice and portions ot'` a district selector and sender for extendinga connection and controlling; such extension.` Fig. shoivs a schematic oiiice selector,` a` por tion `ot a tandem office, af portion of a circuitfby fthe ldial,closing afcircuit 'from SsrOUlld, ,over the back contacter relay 1100, k,front contact ,of .relay 1102Which remains Fig. t shows alpine,operated due to its' slow release character,

tion of a. class switch and ycounting relays torcont-rolling the association of the call announcer with the talking connection; Fig.

shows the manner in which Figs. l to 4 Should bearansed i f,

f Thesedravyings indicate the application the present :invention to such a` system as thatjdisolosed in U. S. Patent 1,505,171,

vgranted to F. A. Stearn `August 19 1924. lt is ojt course, tobje understood that the invention isalso applicable to other systems.`

convenience inr so doing the same numbers hafviebeen. appliedtol such parts taken from the above disclosure asy are used therein. fNo numbers in the third, fourth or fifth hundreds have been. .taken trom the Steam c .sclosure Therefore, the new portions of `F-Wlll v`be givennumbers in the third hundred, those of 4 inthe fourth hundred and those of Fig. 2 in the fifth hundred .,omceselector reference ism'a'de to U. S. Eatent1,5,617,27l to L. Johnson, December The initiation of a call by the subscriber at fsubst'atiohKicausesthe line switch 100 to hunt for an idley district selector and to extend the line tliereto.k An idle sender is then attached to the district `selector `Whereupon a tone is transmitted to the calling subscriber from tone coil 717. Relay 1100 also i and` it Willwbev understood that? all numbers in these hundreds refer exclusivelyftothek presen@disclosure. lFig-2 is divided into tlnee'sectionsby dotted lines,l thel left seo patent.

winding of relay 1190, brush 1108 of the register control switch in its normal position, winding of magnet 1105 of the-first' office code register to battery. rIhis register is advanced one step for each interruptionV of the line circuit and brush 1171 comes to rest on the terminal corresponding to the first digit of the otice code. operated in the circuit of magnet 1105 and,

being slow to release, remains operatedfbe- Relay tween interruptions of its circuit. l 1190 in operating complets a1 circuit from grounthoyer the right front contact of relay y"1102, Contact of relay 1190, through the winding of magnet 111.53 of the register control switch, to battery. Between digits relay 1190 releases, permitting magnet 1113k to advance the register vcontrol switch to connect with the next register.' Brush 1173 ofA the second office code register, `brush 1175 of the third code register, bruslr1168 of the thousands register. brush 1171y ofthe hundreds register, brush 1227 of the tens regis-v ter, brushA 1230 of the units register` and brush 1220 of the stations register are-successively positioned in a similar manner.

*Followino' the completion of registration the translator (not shown) is positioned' from the three office code registers and' the class switch represented by the rectangle 400 is set in a position indicating that the call `Aoilice trunk. The circuit for this purpose may be traced from battery, through the left winding of relay at the tandem oiiice, left back contact of relay 504, left back Contact of relay 505,v upper left winding of repeating coilI 506, office' selector brush501, district selector brush 259, right contacts of cam 220, conductor 262 Aand other intervening` apparatus, cam 744 of the sender control sequence switch which is now standinginposition 9, cam 834 of the sender sequence switch wilnch'is know'in position 12, upper left winding of repeating coil 402, cam 401 of the class sequence switch', through the winding of polarized relay 828, winding of stepping relay 804, upper contact of sender cam 774, windingl of relay 839, upper c'ontacts 'of cam 403, lower left winding of re- .peating coil 402, contacts of cam 824,

through `a compensating` resistance, Contact of cam 841contact of cam 749, back contact of relay 750,' right contacts of cam 219,

Relay 1190-is '527l of that switch'.

brush258, 'winding of relay 528 at the office selector, brush 502, lower left winding oit repeating coil 506, right .back contacts of relays 505 and 504. right winding of relay 503 to ground. vRelay 839 operates and advarices they sender sequence switch to position 14 from which it is advanced to posi- 'tion/16 in the manner described in the Stearn patent. The current is not in the righty direction to' operate relay 823. rRelay 508 also does not operate in this circuit due to the high'resistance of relay 839. When the sender sequence switch reaches position 16, 'the circuit above traced'extends over the lowercontactofv cam 774, outer left back contact of'relay 411and in parallel over the outer leftbaclr Contact of/relay 416, right contacts of'cam 403, lower left winding of repeating coil 402 and thencey as previously traced, ,omitting relay 839y from thek circuit.

`Relay 503 now;loperatesfto indicate to the 'tandem operator that afcall is incomingto her posit-ion.' Wlhilethis relayr may function in any ldesirable manner to signal the operator, an automatic arrangement of the sort disclosed in application Serial No. 213,- 506, tiled August 17, 1927,v in the name of A. Rhodes et al. has been shown by way -of example.

The operation of relay 503 operates relay .i

507 which starts switch 500 hunting` for the trunk and alsoy marks the trunlin the arc When the switch connects'with the trunk, a circuit is completed for relay 508 which stops the switch and performs any vother necessary functions. It also completes a circuit from ground at `its leftfront contact,leftl back contact of relay '509,' middle winding of 'relay 505 to battery.

Relay 505 operates inthis circuit and locks through its outer windings tothe trunk cirthrough resistance 510, right windingl and inner right armature of relay 505, to the lower left winding of repeating` coil 506 and lthe.rii'igconductor of the trunk extending as before traced back over the tip conductoi of the trunk to the upper left winding of repeating coil 506, left armature and winding of relay 505, resistance 5117 to ground.k Relay .508 is `released byy means not shown after ay short time so that the continued operation of relay 505`is dependent upon the sender. The operation of relay 505 opens the circuit of relayl 50? and that relay' releases but switch 500 is heldvby other'means. The cur- 'cuit thus completinor a circuit from battery,

rentin the locking circuit of relay 505 is in 'the reverse direction to that formerly flowing through the windings of relay 503 and therefore relay 823 operates in this circuit.

-Relay 823 in operating closes a circuit from yground-at its front Contact, Contact of' cam 867, contactl of cam 404, right winding of `relayv405,'tobattery, forinitiating the call announcement. l-lowever, a shunt may be ffl closed arou-nd the Winding of" relay 405l extending from'battery,jthrough the* left noninductive Windingof the relay, overy the right back Contact thereof, over the trent cont-act ot relay 406 to the operating circuit ot' relay 405` Relay 406i is operated in av circuit -l'roin battery, over earn 800K belfongingto tl'iesender sequence switch, class cam407, Winding ofl relay 40G, to ground through commutators 301 and` 302 carried by the call announcer mechanism. The conducting and insulating segments of commutator301 are soarranged that relay 4001is operated While the talking` portions of the announcingr drums are effective andy released duringl the sl'ent periods, Therefore, ii the circuit of' relay 405A is completed-at a time Which would correspond to the inidfdlel ot a Word it cannot operate, thus preventing the mutilation of aA signal. Vlhen relay 406 releases at a silentperiod, relay 405 operates complet-ing` thepr-imary circuit of thc `repeating coil 402 which may be traced from the common conductor 308, through the right windings of thercpeating coil, lett 'front contact of relay 405', right haelt contact ot relay 4.13, right back contact of relay 411.1, lower right and upper left contacts ot cani 421, belongingtothe call announcer sequence switch 420, brush 1171,04 the lirst oliice code register in its. set position, through the connected ampl-iiierfand' transformer, bac-lr to the common conductor 303;

The call announcer mechanism shown il,- lustrates one form which such a mechanism may take. It comprises a serlesofdrums having,` opaque and partially transparent sections, the parti-ally transparent sections being` photographic records of the sounds corresponding` to the digits from` 0 to 9. and the stat-ions letters R, M, l and WV, The light from aI sourcefsuch as lamp i504 may he directed by any suital'ile means thrmigh the speech-record to a ph'otoelectric cell such as 305 connected to' one sifd'e ot ya transformer such as 306. The output currentsfroni the transformer are ampliiecli and transmit-ted to the repeating coil 402` over the circuit above traced, Wherethey are inductively transmitted to the interoice circuit abovetiaced, and thereover to the operator at the tandem oiiice. A call announcer mechanism such as disclosed in PatentNe. 13,645,573, patented October `18, 11927, inr the naine ci? H. M; Bascom may also he employed, The register are indicated as beingv those employed in the Stearn patent for controlling callindic-ator impulses. `It is obvious that there might be employed tor this purpose additional arcs on the register switches, or that the multiple connections` to these arcs might lie/transferred from the call indicator equipment to the calli announcer equipment by cams ot the class sequence switch.v

Relay 405 when operated asaboye dew scribed?V also closes a circuit fronr battery, throught'lie Winding ot relalyI 410, inner lett back contact of relay 4511, lett back Contact of relay 413, right front contact of relay 405, front contact of relay-,400, to gi'round over the operating); circuit of relay 405. Re lay 410 operates in this circuit and* closes a locking circuit for itseltthrough the Wind'- ing of relay 411, the. front contact of relay 410, upper contacts ot cam 426, right Contact of cam 427, to ground.y Relay 411 cannot operate at this time being shunted by the operating ground of relay 410; lVhen relay 400 releases at the conclusion of the an nouncement ot the first digit, relay 405 does not release since the shunt around its n'inding is now open. However, the shunt is removed? from relay 411 and that relay operates inthe locking circuit of relay 410. The operation ot relay 411 extends the announc- .ingr circuit from thc primary Winding olf coil 402 over the right back Contact ot relay 413, inner right liront contact oi relay 411', lower right and upper lett' contacts ot cam 422, to brush 1173 ofthe second ollice code register. lVhen relay 400 reoperates at the beginning ot the next talking period a circuit is closed for `relay 412r Afrom battery, through the Windingot that relay, left 'front contact ol relay411, lett hack contact of relay ,413, to ground as previously 'tra-ced. Relay 412 locks throughv the Winding of relay 413but relay 413` does not operate until the end of the talking `period when vrelay 406 againreleases; lith relay- 4'13 operated the announcing circuit eitends over the'right trent contact of relay 413, right back contact of relay 415, lower right and upper `lett contacts ofy cani 423 to llirush 1175501E the third ollice code register. The operation oil relay 406 during the third talkingperiod completes a circuit froni;battery, through the Windingof relay 414, lettbaclr Contact' of relay*` 415, lett front Contact of relay 413, to the right front Contact' ot relay 405 and thenceto groundk as traced. Relay 414 operate's andloclrs through the Windingy olf relay 415, but relay 415 does not operate until relay 40G releases at4 the end ot' the third talking period. The next operation of relay 406 directs the announcing circuit to cam .424but no circuit is completed over that cam with switch 420 in position 1. The operatitm of relay 400` causes relay 416 to operate and lock?.

Since relay 411 is operated at the time that relay 416 operates, the operation ol? the Ilatter relay opens the circuit of' relay S23 and that relay as Well as relay 505 releases. `Relay/416 also closes'a circuit from ground over the upper contact oit cam` 427, outer right contact ol' relay 416, upper lett Contact ol cani 428, Winding of sequence switch magnet 420 'to battery. The call an nouncer switch 420I advanced to pos a ifi till) l lill 3. As switch 420 advances out of vposition 1 relays 410 and 417 release. lVith relay 505 released., and relays 411 and 416 released, the circuit ot relay 823 is again extended to relay 503 but the operation ot relay 503 .is ineitectiyeat this time.

The telephoneset of the tandem operator was connected to the right winding of re,- peating coil 506 over brushes 512 and'513 as soon as switch 500 came to rest, therefore she is ready to receive the call announcement as soon as it is transmitted to her. `When she hears the three digitswhichidentify the otliceI to which the call is to beextended, she selects an idle outgoing trunk to that oilice and inserts the plug 514 of the incoming trunk in the jack 515 ot the outgoing trunk. The insertion of plug 514 in jack 515 completes ra circuit trom battery, through the lett winding of relay 516, left back contacts of relays 517 and 518, upper left winding et repeating coil 519, over the tip of jack 515 and plug 514, upper right winding of repeating coil 506. over the right back contact ot relay 520, winding of relay 521, lower right winding ot' repeating coil 506, rings of plug 514 and jack 515, lower left winding of repeatingl coil. 519, right back contacts ot' relays 51S and 517,Y right winding of relay 516, to ground. relay 516 operates in this circuit to indicate to the operator at the manual olice that a call is incoming, but the current does not flow in the proper direction to operate the polarized relay 521. Although a lamp has been shown for this purpose together with manual listening and ringing keys, it is to be. understood that automatic equipment similar to that shown at--the tandem `oflice might be employed, while manual equipment might be employed at both ollices. Assuming the apparatus to be as shown, the operation oli relay 516 lights lamp 523. In response to the lamp signal the operator closes her listening key 524 connecting her telephone'to the trunk and also closing a circuit from ground, over the auxiliary contact 525, winding of relay 526, to battery. Relay 526 operates, closing a circuit from battery, over its front contact, middle winding ot relay 518, to ground.k Relay 518 operates in this circuit, locking through its outer windings to the circuitfot relay 521. The operation of relay 518 reverses thev current through the winding of relay 521 which now operates. Relay 521 in operating closes a` circuit from ground at its front contact, left back contact ot relay 520, back contact of relay 508, right back contact ot relay 509, middle winding of relay 505, to battery. Relay 505 again locks through its outer windings to the circuit of relay 823, operating the latter relay. Relay` 505 .also closes a circuit from battery, through the Winding ot relay 520, outer right 'trent contact ot relay 505, to ground at the front contact of relay `521. Relay 520 is slow to operate to insurethat the circuit of relay 521 is closed at the outer left front,y contact et relay 505 before it is opened at the right 1 contact of relay 520; Relay 520 closes a circuit from battery, through t-he winding o1 relay 522, back contact ofrelay 509, trent ycontact ot relay 520, front contact ot relay 521, to'ground. Relay 4522A locks through the winding yof relay 509 and its own front contact, to ground, but relay 509 cannot .operate being shunted by the operating ground ot relay 522. The operation of rela 522 closes shunts around resistances 510 and 511, increasing the current through relay 528 so that `in combination with the re-` versed direction of the` current, relay 528, which is both polarized and marginal, may operate. Then the fundamental circuit is openedas described hereinafter, relay 52S releases to establish a talking circuit and otherwise alter the circuits at the otlicc selector as set .forth in the above mentioned Johnson patent.

The operation otrelay 823again operates relay 405 at the begining of a talking period of the call announcer. The announcing circuit now extendsy over the right backA Contact of `relay`413, right back contact o1' relay 411, right 'contacts of cam 421 to brush 1168 of' the thousands register.- The'iirst operation andrelease of relay 406 caused relays 410 and 411 to operate and lock, the locking circuit extending over the upper left and lower rightcontacts of cam 426, the back Contact of relayr414, to ground, at the right contact lll() ot cam 427. During the next talking period n the rannouncing circuit extends over the right contacts et' cam 422 to brush 1.170 ot the hundreds register and relays 412 and 413 operate and lock. During the next talking vperiod'the announcing circuit extends over the right contacts of cam 423 tovbrush 1227 of the tens register and relays' 414 and 415 operate and lock. It will be noted that Ilo with switch 420 in position 3 the locking i i circuit of relays 410 and 411 extends over the lower yright contact of cam 426 and the left back contact of relay 414, so that the operationkof relay 414 yreleases relays 410 and 41.1. During the next period relays 416 and 417 n are operated -but sincerelay 411 is now released, the circuit ot relay 823 is maintained closed. The announcement circuit extends during this period over the right front contacts ofrelays 413 and 415 and the y right back contact of relay 417, contacts of cam 424, to brush 1230 o1 the units register. During the next period the operating circuit yfor the counting relays is extended over the front contact of relay 405, left front contact of relays 413, 415 and 417'and inner. left back contact of relay 411, the Winding of ,relay 410 and battery and relay 419,

f desiernation could `be transmitted.

navarros reoperatcd, locking' fin a circuit extending through the Winding yof `relay 411, the l'right contact of relay 110, the :lettcontact `ot cani 426, the outer right contacted relay 4116 to ground at the ri ght'contar-,toilr cam 427. ,Ait this time vtbe announcing circuit may be traced from the left -iront contact kof relay Li055, over vthe `right 'liront contacts "of relays 4.13, fl-,15 and L17 and the contacts oi Cain 125 -to brush 1220 of the stations register. Then relay L111 operates at the end lof the tilith period, the circuit `ot' lrelay 823 .Lis opened lreleasino' vrelays AS23, 528 and 505. Theopcration or relay 4111 also lcloses a cir cuit from ground, over the Ilett contact Iot cam v i-27, leltiircnt contact o-.t `relay 416, outer rright i'ront lContact -ot relay v 4511, through `.the Winding of relay 750,to battery. The operation of -relay750 also opens the circuit ot relay S28 and serves, as described in the above identiiied patent, to Vadvance the sender to maketallring'selections, `to establish the Aconnection to the distant oiiice and toy release the sender. The restoration of the sender ycloses va circuit (not shown) for advancing sequence switch 420 to its next operating position. ll-Vhile only posi tions 1 and have been shown, it 4is'obvious that Jthe remaining positions ofthe sequence switch may be similarly employed to con trol ucall announcen'ients.- ln fthe -case :of a non-tandem call, the lcla-ss sequence iswitch Would advance sequence switch L120 directly `to posi-tion `3 so that only theuiumeriea These latter circuits have been` omitted for simplicity. y

The opening o'fthe fundamental rcircuit permits relay 505 to release :as Aabove 1nentioned, reconnecting the incoming trunk :to relay 503, openingthe circuit of relay 521 and removing the shunt 4from rthe Winding ofrelay 509, Which relayinowoperates. The release of relay 505 also opensfthe `circuit of relay 520 and that relay releases after an interval due toits slow releasingcharacter. Vith relayr 505-released, the vcircuit lof 'relay 521 vis opened until relay 520 `closes its :back contact. The opening of this circuit per# mits relay 518 at the manual oflice'ito release and extend the `circuit of relay 521 to the Windinus of relay 510 again. Vhen the circuit ot relay 521 is reclosed at thetcontact of relay 520, relay l521 cannot freoperate since 'the current is now in 'the Wrong direction. VVhe-n .the operator at the local manual yoffice has received the called line number shetests the line `jack in lthe `usual manner and kas-` suming' the line to be idle, inserts the `plug 530 inthe jack 531 ot' Athe called line. `lt will be noted that-the sender automatically advances the district selector to talking position Without `Waiting for the called subscriber to be signaled. Therefore, if the manual operator fails to understand the number as announced ibythe sender, she may leave her listening 'key closed and obtain the correct wanted number 'trom the `call-` ingsubscniber. 'She then signals the `wanted subscriber in the usual manner.

When the called subscriber answers a circuit is `'closed 'from "battery, through the winding "of repeating coil 519, Winding'zott :supervisory relay '533, contact ofthe ringing lkey 53e, ring of plug 530 and jaclr531,over 'the subscribers line 532, tip o'f'jaclr 53l'and1plug` `530, contactoi ringing keyf58t, upper .right Winding of repeating coil 519 to ground. Relay 533 'operatesicompleting ,a :circuit rt'rom ground, over its front Contact, Winding of `relay 517, vto"battery. Relay 517 iagain reverses `fthe direction ot current to relay l521 which'reoperates. The operation otr-clay 521 at lits contact closes a circuit from battery, through 'thefwinding ozrelay 5011, liront contact of relay 1509, bach Contact `of irelay 508, `left'back contactwot relay 520 to ground :at'the `'frontfcontact oft relay521. i :Relay 5011 reversesthe connection of lrelay `50S-to the incoming ltrunk ifor supervisor-y` purposes.

'lllhen ithe lcalled subscriber restores his receiver, relay 533 `releases in turn releasing relay 517 :and 'restoring the connection oft changes the direction of the current through the Awinding' oit 'relay 521.causing 'that relay to release. Relay 521 in `turn releases relay 504 .and restoresfthe direction rot Icurrent over the fincoining trunk .preparingi'or release` When `the calling subscriber restores his receiver. f' The release by lthe calling si1bscriber releasesrelay v503 'which may vnow be effective "to display `a disconnect signal (not shown.)` before the vtandem .operato'r." 'llheetandem operator then withdraws plug 51114 from `plug 515 releasing' relay 516 and extinguishing `rlamp 523 as ralsignal lto `the manual operator ato lremoreplug 5301tro1n jack' 531. 'Relays 509 and 522 at lthe tandem oiiiceware .released by means .not shown `when the connection is broken down. i

f1. 'Inawtelep'hone exchange system, :a Vmachine sivitehingoiiice, a tandem oiiice, a manual oiiiee, Vmeans for registering' a .tele-L phonie designation comprising an oiiice designation rand a knumerical .(lesignationsat said Vmachine switching oilice, means for elstablishing taconnection 'from saidanachine switching .office to said tandem ndice, means responsive 4to theiestalilislnnent ctsai'd connection to transmit said otiicewdesignation to 4.said ytandem office, :means-to :thereupon extend said connection tofsaid inanualdii'c and :means `responsive to said extension o transmit said numerical designation to said manual office.

'2. In a ltelephone exchange system, a machine switching roiiice,.a tandem office, ai

manual office, means for registering a telephonie designation comprising an officev designation and a numerical designation atA said machine switching office, means under the control of' said registered office designa` tion for establishing avconnection from said machine switching office to said tandem oifice, means responsive to the establishment of said connection to transmit said ofhce designation to said tandem office, meansto thereupon extend said connection to said manual office, and means responsive to said extension to transmit said numerical designa@ tion to said manual office.

3. In a telephone exchange system, a machine switching office, a tandem office, a `manual office, means for registering a teleplionic designation comprising an office designation and a numerical designation at said machine switching office, means under the control of said registered office designa-l tion for establishing a connection from said machine switching office to said tandem office, means responsive to theestablishnient of said connection to transmit said office designation to said tandem omce, operator controlled means for extending said connection to said manual ofiice, and means automati cally responsive to said extension to transmit said numerical designation to said manual office.

el. In a telephone exchange system, ay machine switcliing office, a tandem, office, a manual office, means for registering .a telephonic designation comprising an office designation and a numerical designation at said machine switching office, means for establishing a connection from said machine switching office to said tandem office, an operators equipment at said tandem office,` means to associate'said operators equipment with said connection, means vresponsive to such association to cause the transmission ofi,

5. In a telephone exchange system, a ma` chine switching office, a tandem? office, a manual office, means for registering a telephonie designation comprising an office des -ignatioii and a numerical designation at said machine switching office, means for establishing a circuit connecting said machine switching office and said tandem office, a polarized relay at said machine switching office in saidconnecting circuit, an operators equipment at said tandem office, means to associate said operators equipment with said circuit, means responsive to such associatioii' to reverse the direction of current flow over said circuit to operate said polarized relay and to thereby initiate the transmission of said office designation to said tandem operator, means for restoring the di: rection of current fiow in said circuit fol` lowing the transmission of said office desig l nation, means controlled by the operator said tandem office to establish a circuit he# tween said tandem office and said manual office, a polarized relay at said tandem office in said latter circuit, operators equipment at 'said manual office, means to asso ciate said manual operators equipment with said second circuit, meansresponsire to such association to reverse the current flow in said second circuit to operate the polarized relay at said tandem office, means responsive to the operation of said last mentioned polarized relay for again reversing the current fiow in said first circuit to operate the polarized relay at said machine switching office, and means responsive to the reoperi tion ofthe polarized relay at said machine switchingofficeto initiate the transmissionof said numerical designation. i

G. In a telephone exchange system, a inachine switching office, a tandem office. a manual office, a sender at said machine switching office, means in said sender to register telephonie designations comprising registers for registering the office designation and registers for registering the numerical designation, means selectable by said registers'for generating currents characteristic of the element-smarking up telephonie designations, means to establish a` connection from A'said machine switchingoffice to said tandem ofiice,means to successii-ely associate saidv registers with said connection, means responsive to'l the establishment of said con-r nectioii to operate saidrassociatingv means to transmit currents characteristic of said office designation to said tandem office, means for extending` said connection to said manualoflice, and means responsive to said extension to reoperate saidv associating means to transmit currents characteristic of said numerical rdesignation to said manual office.

7. Ina telephone exchange system, a inachine switching office, a tandemy office, a manual office, a sender at said machine switching office, means in said sender to register telephonie designations comprising registers for registering the office designartion and*v registers for registering` the nuin'erical designation, means selectable by said registers forgenerating currents characteristie of thel elements making up telephonie designations, means to establish a connection from'said'machine switchingoflice to said tandem office, a series of' counting relays to successively Vassociate said registers with said connection, meansjresponsive to the establishmentfof said connection to operate lili) said relays to trans-mit vcurrents characteristie ot said otiice designation to said tan" dem ollice, means tor extending said connec-y tion to said manual oilice, and means respon-y si ve to said extension to reorieratexsaid relays to transmit currents characteristic of said numerical designation to said manualotiice.

8.1In a tele ahone exchange s fstein' a inachine switching oiiice, tandem oilice, a manual o'lhce, a sender at said machine switching ollice, .means in said sender to register telephonie designations comprising registers tor reeisterinO1 the office designa-` D C D D tionand registers tor registering the numerical designation,v a .call announcing mechanism having a plurality o'll sections "for announcing the elements makin O'u tele phonic designations, said sections being selectable by said registers, means to establish a connection trom said machine switching oiice to said tandem o'liice, means to succes-k sively associate said registerswith said conmanual oi'lice.

9. In a telephone exchange system, a ma` chine switching ollice, a tandem` oiiice, a manual oiiice, a sender at said machine switchingy ofce, means infsaid sender to register telephonie designations comprising` registers for registering the oiiice designation and registers :tor registering the numerical designation in said sender, a call announcing mechanism having a plurality of sections tor announcing the elements making up telephonie designations, said sections being selectable by said registers, means to establish a connection from said machine switching ofice tosaid tandem ofiice, a series ot counting relays to successively associate said registers with said connection, means responsive to the establishment ot' said connection to operate said re lays to announce said office designation to said tandem oiiicc, means for extending said connection to said manual oiiice, and means responsive to said extension to reoperate saidL relays to announce said numerical designation to said manual o'l'iice. n

10. In a telephone exchange system, a machine switching office, a tandem oiiice, a manual ojliice, a calling subscriber at said machine switching oiiice, a called subscriber at said manual oiiice, a sender at said niachine switching oliice, means in said sender to register telephonie designations comprising registers for registering the oice desig nation and registers for registering the numerical designation, a call announcing mechanism y,having a plurality of sections tor announcing the elements making upy telephonie designations, said sections being selectable by said register, means to e lisli a connection `from saidfmachine switching oliice to said tandem oilice, a series of cc`unting relays to successively associate said registers with said connection, means responsive to the establishment of said con nection to operate said relays to announce` said oilice, designation to said tandem soliice, means for extending said connection to said manual oliice, means responsive-to said eX- tension' to reoperate said relays to announce :iid lnumerical designationto said` manual oliice, and means responsive to the completion of the reoperation ot said counting re lays to establish a talking connection be tween said calling subscriber and said `called subscribeix y l1. In a telephone exchange system, a plurality et oiiices, a plurality ot registers at one ot said otiices Ator registering an oHice designation and a plurality of registers `for registering a rnumerical designation, means selectable dby said registers 'for generating currents characteristic oit the elementsgmalting up said designations, means lto establish a connection between said one otiice and another oilice, a series o'lrelays, means to ing up said designations, means to establish a connection between said one oiiice and another o'litice,v a series of relays, meansv to operate said relays to successively associate said o'tiice registers with said connection,

vineans to extend said connection to a third otiice, and means to thereupon reoperate said relays to associate said numerical registers `with said connection.

13. In a telephone system, `a telephone circuit, means for reversing the direction of current flow over said circuit comprising a pair of relays, means controlled by the irst oit said relays to extend said circuit to a current source in one direction through the windings ot the second of said relays, means controlled by said second relay for operating said first relay, and means there-` upon controlled by `said first relay for eX- tending said circuit to said current source in the opposite direction through windings of said iirst relay.

14. In a telephone system, a telephone "as operate said relays to successively associate c circuit, means for reversing the direction of current flow over said circuit comprising a pair/of relays, means controlled by the first of said relays to extend said circuit toay current source in one direction through the windings ot the .se-ond ot said relays, meansv controlled by said second relay for ope/rat ing said first relay through one of its windings, and means thereupon controlled by said first relay for extending said Circuit to said current source in the opposite directionthrough other windings ot said first relay.

15. in a telephone system, a telephone circuit, a polarized relay in said circuit, means for reversing the direction of current iiowy over said circuit to operate said polarized relay comprising a pair of relays,

means controlledby the first of said relays to extend said circuit to a current source in one direction through the windings of the second of said relays, means controlled-by said second relay for operating said iirstf relay, and means thereupon'controlled by polarized relay comprising a pair of relays,

means controlled by the first of said. relays to extend said circuit to a current source in one direction through the windings of the second of said relays, means cont-rolled by said second relay for operating said first relay,r means thereupon controlled by said first-relay for extending said circuit to said current source in the opposite directiony through windings of said first relay, and ineansi'esponsive to the operation of said polarized relay for releasing said first relay to again extend saidfcircui't to said current f source through the windings of said second' relay.L n

l17. In a telephone system, a. telephone circuit, a polarized relay insaid circuit,

means yfor reversing the direction of current flow over `said circuit to operate said rpolarized.relay comprisino a pairof relays, f means controlled by the y iirst of said relays to extend said circuit to a current source 'in one direction through they windings ofthe second of said relays, means controlled by said second relay for operatingy said first relay, means thereupon controlled by said f first relay for extending said circuit to said current source `in the oppositey direction through windings of vsaid first relay, means responsive to the operation of said polarized relayvto transmit a telephonie designation over said'circuit, and means effective followingfthe transmission of said designation to.,

.releasesaid first relayto again extend said circuit tosaid current source through the windings of said second relay.

In witness whereof, I hereunto subscribe ii'iy7name rthis 3rd day 'ofV October, A. D. 192 L HARRY o. CAVERLY. 

